Google unveiled more details about its much-anticipated Chrome OS at a press event at its Mountain View, Calif., campus today, but those who were hoping for a beta release of the OS were in for a disappointment. "We aren't launching the product today. There is no beta today," said Sundar Pichai, vice president of product management. "Our target is the end of next year. We want to be there for the holiday season."

Developers who want a closer look at the project, however, will get their wish. Effective immediately, Google is releasing the Chrome OS code to the public under an open source license, along with the associated design documents. "As of today, the code will be fully open," said Chrome OS director of engineering Matt Papakipos, "which means Google developers will be working on the same tree as external developers."

An OS that is a browserChrome OS is Google's latest attempt to further its concept of browser-based computing, in which the traditional PC desktop is deemphasized in favor of a completely Web-based experience.

At the heart of the new OS is the Chrome browser, which Google has been developing as an alternative to competitors such as Firefox, Internet Explorer, and Opera.

A Chrome OS computer will run no local applications, Pichai explained, and user documents and other data will be maintained via Web-based cloud storage. "With Chrome OS, every application is a Web application," Pichai said.

Applications running on Chrome OS will benefit from the Chrome browser's support for HTML5 standards and its accelerated JavaScript engine, which Pichai said now executes JavaScript 39 times faster than Internet Explorer 8. (Microsoft claims that IE9 will close the gap, although it has given no sense of when IE9 might ship.)

Papakipos also demonstrated Chrome OS applications based on Flash, and he said Google's Native Client technology would also be available on the platform. Native Client is an ActiveX-like technology that provides plug-in capabilities to interact with local system resources. "Everything that comes in Chrome will be available in Chrome OS, and we think Native Client is an important part of this story," Papakipos said.

But Chrome OS will have an additional advantage over browsers running on traditional operating systems, Papakipos said, because it will be tightly integrated with the underlying hardware. That means Web applications running on Chrome OS will be able to take advantage of such features as multiprocessing and GPU acceleration.

Conspicuously absent from Google's presentation, however, was any mention of the L-word. Although Chrome OS is based on the Linux kernel, users should not expect a traditional desktop Linux distribution, à la Suse or Ubuntu.

Instead, Google aims to deliver small, portable Internet devices that power on quickly and deliver users directly into the browser. "It takes about seven seconds for a Chrome OS machine to boot," Pichai said, "and we're working really, really hard to make this shorter."

Netbooks with a Google twistPapakipos demonstrated Chrome OS running on "an off-the-shelf [Asus] Eee PC," but he declined to cite the specific model number, explaining that it was unimportant.

Google doesn't expect users to download Chrome OS and install it on their current PCs. Instead, it will come pre-installed on new, netbook-like devices. "You will have to go and buy a Chrome OS device," Pichai said.

According to Pichai, while today's Chrome OS runs on the current generation of netbooks, Google is working closely with hardware partners to produce its own devices that manufacturers can use as reference designs for Chrome OS-based products.

When the first wave of Chrome OS devices appears next year, they will be small computers in a familiar clamshell form factor, Pichai said, with a screen, a touchpad, and a full-size keyboard. They won't be phones or tablets -- but they also won't have hard drives. "We support only solid-state drives," Pichai said. That insistence on SSDs could help reduce power consumption and contribute to fast startup times.

Pichai declined to speculate what Chrome OS devices will cost when they appear a year from now, and he said Google had not suggested a target price for its manufacturing partners. Lacking hard drives, however, and with limited onboard storage and low processor power, Chrome OS devices could cost considerably less than today's Windows- and Linux-based netbooks.

In addition, Papakipos reiterated that Chrome OS will run on so-called smartbooks based on the ARM processor architecture, which could drive prices even lower.

Web-based computing for everyonePapakipos emphasized that the most important goal of Chrome OS was to create devices that were fast, easy, and enjoyable for the average person to use. "We want to make it a very fast, delightful system to use. We want you to be able to push the On button, it immediately comes on, and you're on the Web as quickly as possible," Papakipos said.

Because Chrome OS applications will be Web-based, users will not need to install or maintain any software. What's more, the system will boot and applications will launch more quickly. "We don't run conventional applications, so we don't need to start up background services for them," Papakipos said.

Papakipos acknowledged that security exploits would inevitably appear for Chrome OS as they do for other platforms, but said Chrome OS will be inherently more secure than traditional operating systems because the latest software updates and security patches would be installed automatically over the Web. Chrome OS devices will be able to detect whether the latest security patches have been installed, Papakipos said, and will even be able to re-image the system while preserving user settings.

Storing user data in the cloud also has advantages, Pichai added, explaining that one goal of Chrome OS was to allow users to move from device to device, or even to share devices, while still preserving their individual experiences.